Depth adjustment mechanism for farm implements

Abstract

An adjustment mechanism for use with farm implements or other equipment utilizes a series of alternating teeth and notches arranged in an arcuate pattern about an axis of adjusting movement on a movable member and a pair of arcuately spaced latching bars on a stationary member of the mechanism. The bars are individually shiftable into and out of engagement with the teeth and notches and are spaced apart such a distance that when either of the bars is in registration with a notch, the other bar is in registration with a tooth. Springs yieldably bias the bars toward the teeth and notches so that the bar aligned with a notch will snap down into the notch while the other bar resides in a standby position abutting the outer end of its tooth. When the seated bar is manually withdrawn from its notch, the movable member becomes unlatched and is free to be indexed one increment in either direction about the adjustment axis, whereupon the bar in the standby position snaps down into a notch brought under that bar, reestablishing a latched condition while the withdrawn bar becomes retained in its standby position by the outer end of its tooth. A double-acting lever having two fulcrum connections with the bars at their outer ends is successively raised and lowered about alternate ones of the fulcrum connections to manipulate the latching bars.

We claim:  
     
       1. In a farm implement having a ground-engaging tool including a coulter assembly provided with a coulter blade, a stationary member, and a movable member that is adjustable relative to the stationary member about an axis of adjustment, the improvement comprising: 
       a plurality of alternating teeth and notches on one of said members arranged in a generally arcuate series concentric with said axis of adjustment;  
       a pair of latching bars on the other of said members,  
       said bars being mutually spaced arcuately about said axis of adjustment and disposed for movement independently of one another into and out of engagement with said series of teeth and notches,  
       said spacing of the bars being such that when either of the bars is in registration with a notch the other bar is in registration with a tooth such that the movable member may be releasably latched in any of a number of selectable positions about said axis by placing a chosen bar in an appropriate notch; and  
       a cleaning tine associated with said movable member for cleaning said coulter blade,  
       said tine being positioned generally transverse to said axis of adjustment and mounted on said movable member for adjustment relative to said coulter blade about said axis of adjustment,  
       said movable member having a cylindrical hub affixed thereto and projecting laterally therefrom,  
       said tine including an elongated working leg portion and a transverse relief spring coil portion having a plurality of side-by-side concentric convolutions,  
       said relief spring coil portion being wrapped around said hub.  
     
     
       2. In a farm implement as claimed in  claim 1 , 
       further comprising a generally L-shaped keeper for said tine secured to an outer end of the hub,  
       said keeper having a first leg extending across said outer end of the hub generally transverse to said axis of adjustment and having a retaining hole,  
       said convolutions of the relief spring coil portion including an outermost convolution having an outturned tang received within said retaining hole,  
       said keeper further having a second inturned leg extending generally parallel to said axis of adjustment,  
       said second leg of the keeper overlying said working leg portion of the tine and underlying a bottom edge of said movable member.  
     
     
       3. In a farm implement as claimed in  claim 2 , 
       said first leg of the keeper further having an inturned protrusion overlying and bearing against said outermost convolution.  
     
     
       4. In a farm implement as claimed in  claim 2 , 
       said first leg of the keeper further having an opening disposed concentrically with respect to said axis of adjustment,  
       said keeper being secured to said hub by a pivot bolt passing through said opening and through said hub.  
     
     
       5. In a farm implement as claimed in  claim 2 , 
       said convolutions of the relief spring coil portion progressively decreasing in diameter as said outermost convolution is approached,  
       the convolution that is closest to said working leg portion being the largest of said convolutions and having an internal diameter that is larger than the exterior diameter of said hub to avoid engaging the hub,  
       said outermost convolution being the smallest of said convolutions and having an internal diameter that is substantially equal to the exterior diameter of the hub for gripping the hub.  
     
     
       6. In a farm implement having a ground-engaging tool including a coulter assembly provided with a coulter blade, a stationary member, and a movable member that is adjustable relative to the stationary member about an axis of adjustment, the improvement comprising: 
       a plurality of alternating teeth and notches on one of said members arranged in a generally arcuate series concentric with said axis of adjustment;  
       a pair of latching bars on the other of said members,  
       said bars being mutually spaced arcuately about said axis of adjustment and disposed for movement independently of one another into and out of engagement with said series of teeth and notches,  
       said spacing of the bars being such that when either of the bars is in registration with a notch the other bar is in registration with a tooth such that the movable member may be releasably latched in any of a number of selectable positions about said axis by placing a chosen bar in an appropriate notch; and  
       a cleaning tine associated with said movable member for cleaning said coulter blade,  
       said tine being positioned generally transverse to said axis of adjustment and mounted on said movable member for adjustment relative to said coulter blade about said axis of adjustment,  
       further comprising a handle operably coupled with the bars for use in manually withdrawing the bars out of the notches,  
       said handle comprising a lever having a fulcrum connection with each of said bars, respectively, whereby the lever may be turned about alternate ones of said fulcrums and in alternate directions to operate the bars.  
     
     
       7. In a farm implement as claimed in  claim 6 , 
       each of said bars having a spring operably coupled therewith for yieldably biasing the bar toward engagement with the teeth and notches.